It is well known that typical freight containers suffer from inflexibility in goods handling. Most trailers are capable of handling bulk goods or piece goods, but not both. As well the trailers which handle bulk goods are usually capable of only unloading those goods by either bottom discharging or end discharging, but not both.
The obvious advantage of trailers which are capable of more than one function is that the same trailer may be used to handle different types of cargoes. This flexibility enables the user to increase the efficiency of the trailer as the trailer would not be required to run empty in search of the single type of load it is capable of carrying.
The term "piece goods" as it is used herein includes discrete items which are commonly handled as individual pieces. The term "bulk goods" refers to known commonly tranported bulk granular material, which is generally free flowing so as to be capable of discharging by gravity action.
Convertible vehicles are known in the art. For example, U.S. Pat. No. 3,917,084 issued Nov. 4, 1975 to Swisher discloses a trailer assembly having a bottom dumping hopper. The hopper is capable of dumping bulk goods onto the ground, or onto a conveyor belt for discharging the bulk goods to the rear of the trailer from the conveyor. The Swisher device is complex in that it requires the use of the conveyor belt. The conveyor comprises many moving components which are susceptible to wear and failure. Further more, the rate at which rear discharging is carried out is dependant upon the speed and size of the conveyor belt. The Swisher vehicle is not capable of carrying and discharging piece goods.
U.S. Pat. No. 4,082,357 issued Apr. 4, 1978 to Schmidt describes a convertible vehicle body for transporting either piece goods or bulk goods. Hinged slope sheets at the ends of the body latch below the ceiling of the body or incline from the ceiling to form a continuation of hoppers contained in the floor. A grating over the hoppers supports piece goods or permits bulk goods to pass through its openings. The slope sheets are raised and lowered by a flexible belt hoist actuated from outside the body through chain and sprocket transmissions mounted under covers between pairs of vertical ribs.
The Schmidt device requires a hoist to raise the sloped sheets. The hoist must be maintained and is susceptible to wear and ultimate failure. The Schmidt patent does not refer to rear discharging of bulk goods.
In U.S. Pat. No. 4,534,596 issued Aug. 13, 1985 to Bonerb, there is disclosed a freight vehicle having a cargo space convertible from that suitable for handling piece goods to that suitable for handling bulk goods. A conventional cargo space has openings in the roof and floor for filling and discharging bulk material. A double wall inflatable bag having its bottom attached to a rigid support platform is positioned in erected condition to handle bulk material. It is movable to a stored position near the roof of the cargo space to handle piece goods.
The Bonerb vehicle requires complex winches and supports to move the rigid support platform from its erected to stored position. As well, a blower is required to inflate the bag and to cause the inner wall of the bag to move inwardly to assist the gravity discharge of the bulk goods. This is an unnecessarily complex and cumbersome system. The use of the bags does not allow for full use of the interior space in the trailer when hauling bulk goods. The Bonerb vehicle cannot end discharge bulk goods.
It is an object of the present invention to provide a vehicle capable of bottom and end discharging of bulk goods. It is an object of the invention to provide this convertibility in a vehicle which is relatively simple to manufacture without unnecessarily adding to the maintainence requirements and unnecessarily complicating the use of the vehicle.
It is a further object of the invention to provide a vehicle capable of bottom and end dumping of bulk goods and rear discharging of piece goods.